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Vitamin D in older people

Published online by Cambridge University Press:  03 March 2014

Miles D Witham*
Affiliation:
Ageing and Health, Medical Research Institute, University of Dundee, UK
Gavin Francis
Affiliation:
Ageing and Health, Medical Research Institute, University of Dundee, UK
*
Address for correspondence: Dr Miles Witham, Ageing and Health, Medical Research Institute, University of Dundee, Ninewells Hospital, Dundee DD1 9SY. Email: [email protected]

Summary

Vitamin D has a wide range of biological effects beyond calcium and bone metabolism, and low 25-hydroxyvitamin D levels have been associated with many disease states in recent years, including cardiovascular disease, diabetes, infections and cancer. Association studies of vitamin D are notoriously prone to confounding and to reverse causality, however, and current intervention trial data for non-skeletal indications have been disappointing. Vitamin D is indicated for treatment of osteomalacia in older people, falls prevention in institutionalized older people, and as adjunctive therapy for osteoporosis. Large trials currently underway will ascertain whether potentially beneficial effects of vitamin D supplementation on all-cause mortality in older people are borne out.

Type
Review Article
Copyright
Copyright © Cambridge University Press 2014 

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References

1Linos, E, Keiser, E, Fu, T, Colditz, G, Chen, S, Tang, JY. Hat, shade, long sleeves, or sunscreen? Rethinking US sun protection messages based on their relative effectiveness. Cancer Causes Control 2011; 22: 1067–71.CrossRefGoogle ScholarPubMed
2Lamberg-Allardt, C. Vitamin D in foods and as supplements. Prog Biophys Mol Biol 2006; 92: 3338.CrossRefGoogle ScholarPubMed
3Macdonald, HM, Mavroeidi, A, Fraser, WDet al.Sunlight and dietary contributions to the seasonal vitamin D status of cohorts of healthy postmenopausal women living at northerly latitudes: a major cause for concern? Osteoporos Int 2011; 22: 2461–72.CrossRefGoogle Scholar
4Battault, S, Whiting, SJ, Peltier, SL, Sadrin, S, Gerber, G, Maixent, JM. Vitamin D metabolism, functions and needs: from science to health claims. Eur J Nutr 2013; 52: 429–41.CrossRefGoogle ScholarPubMed
5Gottfried, E, Rehli, M, Hahn, J, Holler, E, Andreesen, R, Kreutz, M. Monocyte-derived cells express CYP27A1 and convert vitamin D3 into its active metabolite. Biochem Biophys Res Commun 2006; 349: 209–13.CrossRefGoogle ScholarPubMed
6Haussler, MR, Jurutka, PW, Mizwicki, M, Norman, AW. Vitamin D receptor (VDR)-mediated actions of 1alpha,25(OH)(2)vitamin D(3): genomic and non-genomic mechanisms. Best Pract Res Clin Endocrinol Metab 2011; 25: 543–59.CrossRefGoogle Scholar
7Ross, AC, Manson, JE, Abrams, SAet al.The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab 2011; 96: 5358.CrossRefGoogle ScholarPubMed
8Vieth, R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. Am J Clin Nutr 1999; 69: 842–56.CrossRefGoogle ScholarPubMed
9Preece, MA, Tomlinson, S, Ribot, CAet al.Studies of vitamin D deficiency in man. QJM 1975; 44: 575–89.Google ScholarPubMed
10Maxwell, JD.Seasonal variation in vitamin D. Proc Nutr Soc 1994; 53: 533–43.CrossRefGoogle ScholarPubMed
11Hypponen, E, Power, C. Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. Am J Clin Nutr 2007; 85: 860–68.CrossRefGoogle ScholarPubMed
12Hirani, V, Primatesta, P. Vitamin D concentrations among people aged 65 years and over living in private households and institutions in England: population survey. Age Ageing 2005; 34: 485–91.CrossRefGoogle ScholarPubMed
13Hirani, V, Tull, K, Ali, A, Mindell, J. Urgent action needed to improve vitamin D status among older people in England! Age Ageing 2010; 39: 6268.CrossRefGoogle ScholarPubMed
14Francis, RM, Anderson, FH, Patel, S, Sahota, O, van Staa, TP. Calcium and vitamin D in the prevention of osteoporotic fractures. QJM 2006; 99: 355–63.CrossRefGoogle ScholarPubMed
15Dhesi, JK, Moniz, C, Close, JC, Jackson, SH, Allain, TJ. A rationale for vitamin D prescribing in a falls clinic population. Age Ageing 2002; 31: 267–71.CrossRefGoogle Scholar
16Reid, D, Toole, BJ, Knox, Set al.The relation between acute changes in the systemic inflammatory response and plasma 25-hydroxyvitamin D concentrations after elective knee arthroplasty. Am J Clin Nutr 2011; 93: 1006–11.CrossRefGoogle ScholarPubMed
17Martins, D, Wolf, M, Pan, Det al.Prevalence of cardiovascular risk factors and the serum levels of 25-hydroxyvitamin D in the United States: data from the Third National Health and Nutrition Examination Survey. Arch Intern Med 2007; 167: 1159–65.CrossRefGoogle ScholarPubMed
18Isaia, G, Giorgino, R, Rini, GB, Bevilacqua, M, Maugeri, D, Adami, S. Prevalence of hypovitaminosis D in elderly women in Italy: clinical consequences and risk factors. Osteoporos Int 2003; 14: 577–82.CrossRefGoogle ScholarPubMed
19Pfeifer, M, Begerow, B, Minne, HW. Vitamin D and muscle function. Osteoporos Int 2002; 13: 187–94.CrossRefGoogle ScholarPubMed
20Janssen, HC, Samson, MM, Verhaar, HJ. Vitamin D deficiency, muscle function, and falls in elderly people. Am J Clin Nutr 2002; 75: 611–15.CrossRefGoogle ScholarPubMed
21Muir, SW, Montero-Odasso, M. Effect of vitamin D supplementation on muscle strength, gait and balance in older adults: a systematic review and meta-analysis. J Am Geriatr Soc 2011; 59: 2291–300.CrossRefGoogle ScholarPubMed
22Stockton, KA, Mengersen, K, Paratz, JD, Kandiah, D, Bennell, KL. Effect of vitamin D supplementation on muscle strength: a systematic review and meta-analysis. Osteoporos Int 2011; 22: 859–71.Google ScholarPubMed
23Corless, D, Dawson, E, Fraser, Fet al.Do vitamin D supplements improve the physical capabilities of elderly hospital patients? Age Ageing 1985; 14: 7684.CrossRefGoogle ScholarPubMed
24Burleigh, E, McColl, J, Potter, J. Does vitamin D stop inpatients falling? A randomised controlled trial. Age Ageing 2007; 36: 507–13.CrossRefGoogle ScholarPubMed
25Latham, NK, Anderson, CS, Lee, A, Bennett, DA, Moseley, A, Cameron, ID. A randomized, controlled trial of quadriceps resistance exercise and vitamin D in frail older people: the Frailty Interventions Trial in Elderly Subjects (FITNESS). J Am Geriatr Soc 2003; 51: 291–99.CrossRefGoogle ScholarPubMed
26Chapuy, MC, Arlot, ME, Duboeuf, Fet al.Vitamin D3 and calcium to prevent hip fractures in the elderly women. N Engl J Med 1992; 327: 1637–42.CrossRefGoogle ScholarPubMed
27Avenell, A, Gillespie, WJ, Gillespie, LD, O'Connell, D. Vitamin D and vitamin D analogues for preventing fractures associated with involutional and post-menopausal osteoporosis. Cochrane Database Syst Rev 2009; CD000227.Google ScholarPubMed
28Bischoff-Ferrari, HA, Willett, WC, Orav, EJet al.A pooled analysis of vitamin D dose requirements for fracture prevention. N Engl J Med 2012; 367: 4049.CrossRefGoogle ScholarPubMed
29Grant, AM, Avenell, A, Campbell, MKet al.Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial. Lancet 2005; 365: 1621–28.Google ScholarPubMed
30Smith, H, Anderson, F, Raphael, H, Maslin, P, Crozier, S, Cooper, C. Effect of annual intramuscular vitamin D on fracture risk in elderly men and women – a population-based, randomized, double-blind, placebo-controlled trial. Rheumatology (Oxford) 2007; 46: 1852–57.CrossRefGoogle ScholarPubMed
31Sanders, KM, Stuart, AL, Williamson, EJet al.Annual high-dose oral vitamin D and falls and fractures in older women: a randomized controlled trial. JAMA 2010; 303: 1815–22.CrossRefGoogle ScholarPubMed
32Burgaz, A, Orsini, N, Larsson, SC, Wolk, A. Blood 25-hydroxyvitamin D concentration and hypertension: a meta-analysis. J Hypertens 2011; 29: 636–45.CrossRefGoogle ScholarPubMed
33Kunutsor, SK, Apekey, TA, Steur, M. Vitamin D and risk of future hypertension: meta-analysis of 283,537 participants. Eur J Epidemiol 2013; 28: 205–21.CrossRefGoogle ScholarPubMed
34Almirall, J, Vaqueiro, M, Bare, ML, Anton, E. Association of low serum 25-hydroxyvitamin D levels and high arterial blood pressure in the elderly. Nephrol Dial Transplant 2010; 25: 503–9.CrossRefGoogle ScholarPubMed
35Beveridge, LA, Witham, MD. Vitamin D and the cardiovascular system. Osteoporos Int 2013; 24: 2167–80.CrossRefGoogle ScholarPubMed
36Wang, TJ, Pencina, MJ, Booth, SLet al.Vitamin D deficiency and risk of cardiovascular disease. Circulation 2008; 117: 503–11.CrossRefGoogle ScholarPubMed
37Witham, MD, Nadir, MA, Struthers, AD. Effect of vitamin D on blood pressure: a systematic review and meta-analysis. J Hypertens 2009; 27: 1948–54.CrossRefGoogle ScholarPubMed
38Forman, JP, Scott, JB, Ng, Ket al.Effect of vitamin D supplementation on blood pressure in blacks. Hypertension 2013; 61: 779–85.CrossRefGoogle ScholarPubMed
39Witham, MD, Price, RJ, Struthers, ADet al.Cholecalciferol treatment to reduce blood pressure in older patients with isolated systolic hypertension: the VitDISH randomized controlled trial. JAMA Intern Med 2013; 173: 1672–79.Google ScholarPubMed
40Pittas, AG, Chung, M, Trikalinos, Tet al.Systematic review: Vitamin D and cardiometabolic outcomes. Ann Intern Med 2010; 152: 307–14.CrossRefGoogle ScholarPubMed
41Pittas, AG, Sun, Q, Manson, JE, Dawson-Hughes, B, Hu, FB. Plasma 25-hydroxyvitamin D concentration and risk of incident type 2 diabetes in women. Diabetes Care 2010; 33: 2021–23.CrossRefGoogle ScholarPubMed
42Autier, P, Boniol, M, Pizot, C, Mullie, P. Vitamin D status and ill health: a systematic review. Lancet Diabetes Endocrinol 2013 (epub ahead of print; doi.org/10.1016/S2213-8587(13)70165-7).Google ScholarPubMed
43Ponsonby, AL, Pezic, A, Ellis, Jet al.Variation in associations between allelic variants of the vitamin D receptor gene and onset of type 1 diabetes mellitus by ambient winter ultraviolet radiation levels: a meta-regression analysis. Am J Epidemiol 2008; 168: 358–65.CrossRefGoogle Scholar
44George, PS, Pearson, ER, Witham, MD. Effect of vitamin D supplementation on glycaemic control and insulin resistance: a systematic review and meta-analysis. Diabet Med 2012; 29: e14250.CrossRefGoogle ScholarPubMed
45Avenell, A, Cook, JA, Maclennan, GS, McPherson, GC. Vitamin D supplementation and type 2 diabetes: a substudy of a randomised placebo-controlled trial in older people (RECORD trial, ISRCTN 51647438). Age Ageing 2009; 38: 606–9.CrossRefGoogle ScholarPubMed
46Scragg, R. Vitamin D and public health: an overview of recent research on common diseases and mortality in adulthood. Public Health Nutr 2011; 14: 1515–32.CrossRefGoogle Scholar
47Dobnig, H, Pilz, S, Scharnagl, Het al.Independent association of low serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels with all-cause and cardiovascular mortality. Arch Intern Med 2008; 168: 1340–49.CrossRefGoogle Scholar
48Elamin, MB, Abu Elnour, NO, Elamin, KBet al.Vitamin D and cardiovascular outcomes: a systematic review and meta-analysis. J Clin Endocrinol Metab 2011; 96: 1931–42.CrossRefGoogle ScholarPubMed
49Poole, KE, Loveridge, N, Barker, PJet al.Reduced vitamin D in acute stroke. Stroke 2006; 37: 243–45.CrossRefGoogle ScholarPubMed
50Chowdhury, R, Stevens, S, Ward, H, Chowdhury, S, Sajjad, A, Franco, OH. Circulating vitamin D, calcium and risk of cerebrovascular disease: a systematic review and meta-analysis. Eur J Epidemiol 2012; 27: 581–91.CrossRefGoogle ScholarPubMed
51Sun, Q, Pan, A, Hu, FB, Manson, JE, Rexrode, KM. 25-Hydroxyvitamin D levels and the risk of stroke: a prospective study and meta-analysis. Stroke 2012; 43: 1470–77.CrossRefGoogle ScholarPubMed
52Witham, MD, Dove, FJ, Sugden, JA, Doney, AS, Struthers, AD. The effect of vitamin D replacement on markers of vascular health in stroke patients – a randomised controlled trial. Nutr Metab Cardiovasc Dis 2012; 22: 864–70.CrossRefGoogle ScholarPubMed
53Shane, E, Mancini, D, Aaronson, Ket al.Bone mass, vitamin D deficiency, and hyperparathyroidism in congestive heart failure. Am J Med 1997; 103: 197207.CrossRefGoogle ScholarPubMed
54Zittermann, A, Schleithoff, SS, Tenderich, G, Berthold, HK, Korfer, R, Stehle, P. Low vitamin D status: a contributing factor in the pathogenesis of congestive heart failure? J Am Coll Cardiol 2003; 41: 105–12.CrossRefGoogle ScholarPubMed
55Gotsman, I, Shauer, A, Zwas, DRet al.Vitamin D deficiency is a predictor of reduced survival in patients with heart failure; vitamin D supplementation improves outcome. Eur J Heart Fail 2012; 14: 357–66.CrossRefGoogle ScholarPubMed
56Witham, MD. Vitamin D in chronic heart failure. Curr Heart Fail Rep 2011; 8: 123–30.CrossRefGoogle ScholarPubMed
57Witham, MD, Crighton, LJ, Gillespie, ND, Struthers, AD, McMurdo, ME. The effects of vitamin D supplementation on physical function and quality of life in older patients with heart failure: a randomized controlled trial. Circ Heart Fail 2010; 3: 195201.CrossRefGoogle ScholarPubMed
58Schleithoff, SS, Zittermann, A, Tenderich, G, Berthold, HK, Stehle, P, Koerfer, R. Vitamin D supplementation improves cytokine profiles in patients with congestive heart failure: a double-blind, randomized, placebo-controlled trial. Am J Clin Nutr 2006; 83: 754–59.CrossRefGoogle ScholarPubMed
59Boxer, RS, Kenny, AM, Schmotzer, BJ, Vest, M, Fiutem, JJ, Pina, II. A randomized controlled trial of high-dose vitamin D3 in patients with heart failure. JACC Heart Fail 2013; 1: 8490.CrossRefGoogle ScholarPubMed
60Witte, KK, Nikitin, NP, Parker, ACet al.The effect of micronutrient supplementation on quality-of-life and left ventricular function in elderly patients with chronic heart failure. Eur Heart J 2005; 26: 2238–44.CrossRefGoogle ScholarPubMed
61Black, PN, Scragg, R. Relationship between serum 25-hydroxyvitamin D and pulmonary function in the third national health and nutrition examination survey. Chest 2005; 128: 3792–98.CrossRefGoogle ScholarPubMed
62Janssens, W, Bouillon, R, Claes, Bet al.Vitamin D deficiency is highly prevalent in COPD and correlates with variants in the vitamin D-binding gene. Thorax 2010; 65: 215–20.CrossRefGoogle ScholarPubMed
63Wright, RJ. Make no bones about it: increasing epidemiologic evidence links vitamin D to pulmonary function and COPD. Chest 2005; 128: 3781–83.CrossRefGoogle ScholarPubMed
64Lehouck, A, Mathieu, C, Carremans, Cet al.High doses of vitamin D to reduce exacerbations in chronic obstructive pulmonary disease: a randomized trial. Ann Intern Med 2012; 156: 105–14.CrossRefGoogle ScholarPubMed
65Martineau, AR, Timms, PM, Bothamley, GHet al.High-dose vitamin D(3) during intensive-phase antimicrobial treatment of pulmonary tuberculosis: a double-blind randomised controlled trial. Lancet 2011; 377: 242–50.CrossRefGoogle ScholarPubMed
66Gandini, S, Boniol, M, Haukka, Jet al.Meta-analysis of observational studies of serum 25-hydroxyvitamin D levels and colorectal, breast and prostate cancer and colorectal adenoma. Int J Cancer 2011; 128: 1414–24.CrossRefGoogle ScholarPubMed
67Lappe, JM, Travers-Gustafson, D, Davies, KM, Recker, RR, Heaney, RP. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr 2007; 85: 1586–91.CrossRefGoogle ScholarPubMed
68Wactawski-Wende, J, Kotchen, JM, Anderson, GLet al.Calcium plus vitamin D supplementation and the risk of colorectal cancer. N Engl J Med 2006; 354: 684–96.CrossRefGoogle ScholarPubMed
69Parekh, N, Chappell, RJ, Millen, AE, Albert, DM, Mares, JA. Association between vitamin D and age-related macular degeneration in the Third National Health and Nutrition Examination Survey, 1988 through 1994. Arch Ophthalmol 2007; 125: 661–69.CrossRefGoogle ScholarPubMed
70Golan, S, Shalev, V, Treister, G, Chodick, G, Loewenstein, A. Reconsidering the connection between vitamin D levels and age-related macular degeneration. Eye (Lond) 2011; 25: 1122–29.CrossRefGoogle ScholarPubMed
71Dietrich, T, Joshipura, KJ, Dawson-Hughes, B, Bischoff-Ferrari, HA. Association between serum concentrations of 25-hydroxyvitamin D3 and periodontal disease in the US population. Am J Clin Nutr 2004; 80: 108–13.Google ScholarPubMed
72Krall, EA, Wehler, C, Garcia, RI, Harris, SS, Dawson-Hughes, B. Calcium and vitamin D supplements reduce tooth loss in the elderly. Am J Med 2001; 111: 452–56.CrossRefGoogle ScholarPubMed
73Avenell, A, Cook, JA, Maclennan, GS, Macpherson, GC. Vitamin D supplementation to prevent infections: a sub-study of a randomised placebo-controlled trial in older people (RECORD trial, ISRCTN 51647438). Age Ageing 2007; 36: 574–77.CrossRefGoogle ScholarPubMed
74Avenell, A, Campbell, MK, Cook, JAet al.Effect of multivitamin and multimineral supplements on morbidity from infections in older people (MAVIS trial): pragmatic, randomised, double blind, placebo controlled trial. BMJ 2005; 331: 324–29.CrossRefGoogle ScholarPubMed
75Jorde, R, Witham, M, Janssens, Wet al.Vitamin D supplementation did not prevent influenza-like illness as diagnosed retrospectively by questionnaires in subjects participating in randomized clinical trials. Scand J Infect Dis 2012; 44: 126–32.CrossRefGoogle Scholar
76Llewellyn, DJ, Lang, IA, Langa, KMet al.Vitamin D and risk of cognitive decline in elderly persons. Arch Intern Med 2010; 170: 1135–41.CrossRefGoogle ScholarPubMed
77Rossom, RC, Espeland, MA, Manson, JEet al.Calcium and vitamin D supplementation and cognitive impairment in the women's health initiative. J Am Geriatr Soc 2012; 60: 2197–205.CrossRefGoogle ScholarPubMed
78Jorde, R, Sneve, M, Figenschau, Y, Svartberg, J, Waterloo, K. Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial. J Intern Med 2008; 264: 599609.CrossRefGoogle ScholarPubMed
79Zittermann, A, Iodice, S, Pilz, S, Grant, WB, Bagnardi, V, Gandini, S. Vitamin D deficiency and mortality risk in the general population: a meta-analysis of prospective cohort studies. Am J Clin Nutr 2012; 95: 91100.CrossRefGoogle ScholarPubMed
80Durup, D, Jorgensen, HL, Christensen, J, Schwarz, P, Heegaard, AM, Lind, B. A reverse J-shaped association of all-cause mortality with serum 25-hydroxyvitamin D in general practice: the CopD study. J Clin Endocrinol Metab 2012; 97: 2644–52.CrossRefGoogle ScholarPubMed
81Rejnmark, L, Avenell, A, Masud, Tet al.Vitamin D with calcium reduces mortality: patient level pooled analysis of 70,528 patients from eight major vitamin D trials. J Clin Endocrinol Metab 2012; 97: 2670–81.CrossRefGoogle Scholar
82Jackson, RD, LaCroix, AZ, Gass, Met al.Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med 2006; 354: 669–83.CrossRefGoogle ScholarPubMed
83Watson, KE, Abrolat, ML, Malone, LLet al.Active serum vitamin D levels are inversely correlated with coronary calcification. Circulation 1997; 96: 1755–60.CrossRefGoogle ScholarPubMed
84Gale, CR, Robinson, SM, Harvey, NCet al.Maternal vitamin D status during pregnancy and child outcomes. Eur J Clin Nutr 2008; 62: 6877.CrossRefGoogle ScholarPubMed
85Hypponen, E, Berry, DJ, Wjst, M, Power, C. Serum 25-hydroxyvitamin D and IgE – a significant but nonlinear relationship. Allergy 2009; 64: 613–20.CrossRefGoogle Scholar
86Bolland, MJ, Avenell, A, Baron, JAet al.Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010; 341: c3691.CrossRefGoogle ScholarPubMed
87Bischoff-Ferrari, HA, Giovannucci, E, Willett, WC, Dietrich, T, Dawson-Hughes, B. Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes. Am J Clin Nutr 2006; 84: 1828.CrossRefGoogle ScholarPubMed
88Romagnoli, E, Mascia, ML, Cipriani, Cet al.Short and long-term variations in serum calciotropic hormones after a single very large dose of ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) in the elderly. J Clin Endocrinol Metab 2008; 93: 3015–20.CrossRefGoogle ScholarPubMed
89Aloia, JF, Patel, M, Dimaano, Ret al.Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration. Am J Clin Nutr 2008; 87: 1952–58.CrossRefGoogle ScholarPubMed
90Wood, AD, Secombes, KR, Thies, Fet al.Vitamin D3 supplementation has no effect on conventional cardiovascular risk factors. A parallel-group, double-blind, placebo-controlled RCT. J Clin Endocrinol Metab 2012; 97: 3557–68.CrossRefGoogle ScholarPubMed
91Hoeck, HC, Li, B, Qvist, P. Changes in 25-Hydroxyvitamin D3 to oral treatment with vitamin D3 in postmenopausal females with osteoporosis. Osteoporos Int 2009; 20: 1329–35.CrossRefGoogle ScholarPubMed
92Autier, P, Gandini, S, Mullie, P. A systematic review: influence of vitamin D supplementation on serum 25-hydroxyvitamin D concentration. J Clin Endocrinol Metab 2012; 97: 2606–13.CrossRefGoogle ScholarPubMed
93Zittermann, A, Ernst, JB, Gummert, JF, Borgermann, J. Vitamin D supplementation, body weight and human serum 25-hydroxyvitamin D response: a systematic review. Eur J Nutr 2013 (epub ahead of print; doi 10.1007/s00394-013-0634-3).Google ScholarPubMed
94Chel, V, Wijnhoven, HA, Smit, JH, Ooms, M, Lips, P. Efficacy of different doses and time intervals of oral vitamin D supplementation with or without calcium in elderly nursing home residents. Osteoporos Int 2008; 19: 663–71.CrossRefGoogle ScholarPubMed
95Jean, G, Terrat, JC, Vanel, Tet al.Evidence for persistent vitamin D 1-alpha-hydroxylation in hemodialysis patients: evolution of serum 1,25-dihydroxycholecalciferol after 6 months of 25-hydroxycholecalciferol treatment. Nephron Clin Pract 2008; 110: c5865.CrossRefGoogle ScholarPubMed
96Molina, P, Gorriz, JL, Molina, MDet al.The effect of cholecalciferol for lowering albuminuria in chronic kidney disease: a prospective controlled study. Nephrol Dial Transplant 2014; 29: 97109.CrossRefGoogle ScholarPubMed